Flexible polyvinyl chloride compounds have many applications in sealing and gasketing. Such compounds are, for example, used to form the gaskets which seal refrigerator and freezer doors. The flexible polyvinyl chloride compounds used to seal refrigerator and freezer doors must be compatible with the surfaces with which they will come in contact. The gasketing compound must not change the properties of the in-contact surface, or mar or otherwise alter the appearance of the in-contact surface and especially not stick, soften the paint, nor cause the paint to adhere to the gasket.
Manufacturers of refrigerators and freezers desire to use pre-painted steel in fabricating their products. Such repainted steel is subjected to forming operations which produces sharp bend radii in the paint layer as the steel is formed into the desired shape. Small cracks (micro-cracks) in the painted surface may develop in the vicinity of the sharp bend radii. Upon exposure to the environment, these micro-cracks begin to rust and produce a surface mottled with rust and streaks of rust.
To address this micro-crack phenomenon, paint manufacturers produced "softer" paints which allow the paint film to stretch around the sharp bends and maintain a continuous painted surface. Such "softer" paints which eliminated the microcracking phenomenon demonstrated incompatibility with existing gasket compositions. This invention teaches the composition of a novel flexible polyvinyl chloride gasketing material with low plasticizer migration and the process employed to form such gaskets. These gaskets significantly reduce the marring of the pre-painted surface which they contact.